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Macintosh PowerBook 145/160/170 battery replacement

Ahh you beat me to it, I’ve been looking forward to trying that :D well done! Now we just have to design the battery holders within the casing.

So, two groups of five 2500mAh cells in parallel. I’m a little surprised as I couldn’t get a 100 to run on five cells (needed six - 7.2V) but the 100 is totally different of course, being intended for SLA. Good to know the 1xx can cope with about 6V, being designed for NiCd.
 
alexGS said:
Ahh you beat me to it, I’ve been looking forward to trying that :D well done! Now we just have to design the battery holders within the casing.
Click to expand...
I don't think there is any room left for a ten cell AA holder. If you manage to stuff one inside, you hands down win my "Swole Brain of the Year" award.
alexGS said:
Good to know the 1xx can cope with about 6V, being designed for NiCd.
Click to expand...
Ni-Cd and Ni-Mh are interchangable; charging circuits designed for Ni-Cd should handle Ni-Mh perfectly fine. Although, my pack seems to get a bit toasty with the AA's instead of the green mystery cells.
On a full charge my pack will peak at 7V, then float around 6V before dropping off.
 
You should really add that thermal fuse, especially if it’s getting toasty. Good work though, I need to rebuild one of mine as well.
 
luRaichu said:
I don't think there is any room left for a ten cell AA holder. If you manage to stuff one inside, you hands down win my "Swole Brain of the Year" award.
Click to expand...

Oh - lol, absolutely agree - I didn’t mean a prefabricated holder, I meant to design spaces for the cells into the 3D-printed part, with terminal plates or - as I use - CAT5 wires stripped and threaded through holes to make contact. Non-tabbed cells are a lot cheaper and easier to get here than tabbed cells. I suppose spot-welding strips on is easier, but more difficult for others to reproduce :) Actually even non-tabbed cells are relatively expensive so it might be a while before I get around to this
 
Are all of you that rebuilt batteries charging them outside of the PowerBook or inside?

I was looking into a rebuilding a pack for my PowerBook 160 but I'm not comfortable attempting to charge within the PowerBook until I better understand what the charge algorithm is within the PowerBook.

The stock pack had 2 parallel sets of 5 cells, which I believe were A-size rechargeable NiCDs at 1.2V each. I can rebuild using 2 parallel sets of 5 NiMH cells. But this is essentially two packs of 5 NiMH cells and I don't believe it's safe to charge two NiMH packs in parallel due to the potential risk of overcharging one of the two packs depending on the charging algorithm used.
 
I think how I interpret that is the power brick itself is supplying the power both to the PowerBook and charging the battery by sending it voltage?

But there has to be something that stops charging the battery when it's full. Usually that's some type of delta peak detection or something, it can't be that it's just constantly charging the battery? Or is the stock setup such that the battery is constantly being trickle charged at a low rate instead of a higher speed charge?

I just remember from back in my radio control racing days that the consensus was never to charge two NiMH packs in parallel as it will potentially cause an over charge of one of the two and damage the battery pack.

So it's not clear to me (given even the stock battery is two parallel sets of NiCDs) how the charging is done, and that makes me uncomfortable wiring up two NiMH packs together and allowing it to charge while inserted inside the PowerBook (via the power brick).
 
jmacz said:
Are all of you that rebuilt batteries charging them outside of the PowerBook or inside?

I was looking into a rebuilding a pack for my PowerBook 160 but I'm not comfortable attempting to charge within the PowerBook until I better understand what the charge algorithm is within the PowerBook.

The stock pack had 2 parallel sets of 5 cells, which I believe were A-size rechargeable NiCDs at 1.2V each. I can rebuild using 2 parallel sets of 5 NiMH cells. But this is essentially two packs of 5 NiMH cells and I don't believe it's safe to charge two NiMH packs in parallel due to the potential risk of overcharging one of the two packs depending on the charging algorithm used.
Click to expand...
I charge it inside…
Now I have two packs in parallel and all seems good. I have a thermal fuse to prevent overheating risks.
 
Well, results are pretty poor...

AA-size 10 cell NiMH Pack - only got around 30 minutes after what the PB thought was a full charge. This 30 minutes calculated by how long it takes Battery Amnesia to drain the pack.

A-size 10 cell NiCD Pack (new Sanyo 1700 cells from OnlyBatteries) - only got around 24 minutes after what the PB thought was a full charge. Again via Battery Amnesia.

Having watched the charging of the A-size NiCD pack, I am not convinced it's fully charging. I know the pack was only around 50% but after putting it into the PB160 to charge, it reached 100% within 10 minutes, probably closer to 5 minutes. That's not right. Given the only inputs to the battery are the +/- terminals, it must be determining current charge state via the voltage.

I'm charging the now drained A-size pack via an external PB160 2 slot charger right now. If that doesn't make a difference, I'll attempt to charge it using an external RC race pack charger I have.
 
I charged the A-size pack via the external PB160 charger (the one that has two slots and can charge two batteries at once). It took a while to charge but the light finally went green after hours.

Then I tested again via Battery Amnesia. This time it took 87 minutes to discharge. Hmm... that suggests I'm getting a false reading in the machine about the battery being full. Or perhaps I need to wait for a few full charge cycles first?
 
Leave it plugged in overnight with the laptop shut off. That got my now dead aftermarket pack to go from a couple minutes of charge to around 40. PowerBook would think it was full when it clearly wasn’t. Unfortunately it never really calibrated successfully, and later I found out the cells were leaking so any life I was getting was fleeting.
 
I left it on the external charger overnight. Running it through Battery Amnesia again and the pack seems to be getting stronger. Yesterday's discharge was 87 minutes as I mentioned. Right now it's at 95 minutes and Battery Amnesia is saying there's still 23% left (although looking at the curve, it looks like it's about to tank soon). The curve is interesting.. it starts steep (from 100% to 70%-ish) and then it levels off for a while and then at the end nose dives again (which is where it's at now). Looks like it will finish over 100 minutes though.

I guess I will have to ignore the 100% charge indicator in the System (DA, various tools, etc) and just know that it has to sit there for a few hours to charge all the way.

But based on these discharge times, looks like these new "A" size Sanyo cells (1700mAH) from OnlyBatteries are working fine as replacements.
 
I left the battery charging in the PB half the day yesterday and overnight. Booted today and saw 100% on the battery level, ran Battery Amnesia and it tanked immediately. Lost power in about 10 minutes.

Something's clearly wrong with the charging from the PB. Will need to trace that out to see why.
 
Dug my PowerBook 180 out of storage again, I want to build a new battery pack.
The 3D printed case on my previous battery didn't include rails for the battery door - I appended them incorrectly in the model and they weren't printed. Also the brass strips I used as battery contacts were too thick.
I don't own a spot welder so I thought I could get away with soldering directly on the battery cell terminals, but I think it is very easy to damage your cells this way.

jcs published his battery case model, It's the best design I've seen so far with door rails included.
Like the jcs battery I would also want to use a premade NiMH pack this time. Soldering AAs are just too much of a hack
 
pfuentes69 said:
I made myself a quick&dirt solution for my 145B and now that I'm reading this post, I'd like to ask for some advice, in case I did something stupid or dangerous...
This is my mastery job:
View attachment 43025

For not making it too basic, I tucked a thermofuse (65ºC) in the sleeve.
It seems to work fine, it charges and I can use the PB for maybe 20-30 minutes with it (using a BlueSCSI). I don't really need to use it on battery, it was just for the fun, and also because the old cells were starting to leak.

Do you see a potential problem here?
Click to expand...
Just wondering if this setup is safe to use, I am able to source a pack and fuse like this easily and would prefer to use this setup if possible
 
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